Question

a shopkeeper bought two TV 10000 each. he sold one at a profit 10percent and other at a loss 10 percent. find whether he made an overall profit or loss

Answer 1

if cost price of 2 article is same then use this formula = (profit or loss + loss or profit )/2
=[ 10 + (-10) ]/2 = (10-10)/2 = 0%
means neither gain nor loss.

Answer 2

Given, u=20m/s

t

1

=5s

t

2

=8s

Graph: (Refer to Image)

(1) Distance travelled in first 5 sec= area of ABDE= 20×s=80m

(2) Distance travelled after the brakes are applied (area of BCD)=

2

1

×8×5=20m

(3) Total distance travelled= AreaofABCDE+AreaofBCD=80+20=100m

(4) Acceleration during the first 5 sec= 0, because uniform velocity.

(5) Acceleration during the last 8 sec= v=0,u=20m/s,t=8sec

⇒v=u+at⇒0=20+a(8)

⇒a=−2.5m/s

2

(slope of the line DC